Radioactive iodine adsorbent, method for producing radioactive iodine adsorbent, and method for processing radioactive iodine

Abstract

A radioactive iodine adsorbent is obtained by supporting silver on a high-silica zeolite in which a hydroxyl nest present inside the high-silica zeolite is converted into a Si—O—Si bond, and the high-silica zeolite is at least any selected from the group consisting of a chabazite (CHA)-type zeolite, a mordenite (MOR)-type zeolite, and a clinoptilolite (CLP)-type zeolite.

1 . A radioactive iodine adsorbent obtained by supporting silver on a high-silica zeolite in which a hydroxyl nest present inside the high-silica zeolite is converted into a Si—O—Si bond, wherein the high-silica zeolite is at least any selected from the group consisting of a chabazite (CHA)-type zeolite, a mordenite (MOR)-type zeolite, and a clinoptilolite (CLP)-type zeolite. 
     
     
         2 . The radioactive iodine adsorbent according to  claim 1 , wherein a SiO 2 /Al 2 O 3 molar ratio of the high-silica zeolite is more than 2 and 100 or less. 
     
     
         3 . The radioactive iodine adsorbent according to  claim 1 , wherein an amount of the supported silver is 1 to 15 mass %. 
     
     
         4 . A method for producing a radioactive iodine adsorbent obtained by supporting silver on a high-silica zeolite in which a hydroxyl nest present inside the high-silica zeolite is converted into a Si—O—Si bond, wherein the high-silica zeolite is at least any selected from the group consisting of a chabazite (CHA)-type zeolite, a mordenite (MOR)-type zeolite, and a clinoptilolite (CLP)-type zeolite. 
     
     
         5 . The method for producing a radioactive iodine adsorbent according to  claim 4 , wherein the hydroxyl nest is converted into the Si—O—Si bond by a heat treatment at 500 to 700° C. 
     
     
         6 . The method for producing a radioactive iodine adsorbent according to  claim 4 , wherein a SiO 2 /Al 2 O 3  molar ratio of the high-silica zeolite is 2 to 100. 
     
     
         7 . The method for producing a radioactive iodine adsorbent according to  claim 4 , wherein an amount of the supported silver is 1 to 15 mass %. 
     
     
         8 . A method for processing radioactive iodine comprising a step of adding a reductant to a waste liquid drained from a nuclear facility to convert the waste liquid into an acidic solution, and a step of passing the acidic solution through the radioactive iodine adsorbent according to  claim 1 .